1. Technical Field
The present invention relates to a semiconductor device used in a personal computer, a cell phone, or the like, to a mounting structure using the semiconductor device, to an electro-optical device using the semiconductor device, to a method of manufacturing the electro-optical device, and to an electronic apparatus using the electro-optical device.
2. Related Art
Generally, as display devices of electronic apparatuses, such as a personal computer or a cell phone, liquid crystal display devices are used. A semiconductor device such as a liquid crystal driving IC is mounted in the liquid crystal display device by a flip chip mounting method.
Meanwhile, recently, electronic apparatuses, such as personal computers and cell phones, are required to be small-sized while having a high performance. Therefore, it is required to decrease distances between wiring lines or terminals on a liquid crystal panel, that is, to make the pitch narrower. To cope with this, it is required to make the pitch of bumps of a semiconductor device narrower, that is, to make bumps of a semiconductor device have a high aspect ratio.
However, in the above-mentioned flip chip mounting method, in order to increase the height of bumps, a larger amount of metal needs to be used, the manufacturing process becomes complicated, and the manufacturing cost increases.
Accordingly, there has been proposed an external connecting protrusion which has at least a projecting body formed in the vicinity of an electrode of a semiconductor chip and a conductor continuously formed on the electrode and projecting body (for example, see JP-A-2001-110831 (paragraphs [0006] to [0028] and FIG. 5)). Also, there has been proposed a method of manufacturing a semiconductor device which includes a process of forming a resin layer in the semiconductor device, except for electrodes; a process of patterning conductive layers on the electrodes and the resin layer in accordance with a predetermined pattern of protrusions; and a process of removing the resin layer located between the conductive layers by using the patterned conductive layers as masks so as to form protrusions (for example, see JP-A-2004-186333 (paragraphs [0008] to [0013] and FIG. 4)).
According to the above-mentioned method, for example, the related art disclosed in JP-A-2001-110831, it is possible to improve the aspect ratio and to reduce the usage of metal as a material. However, for example, when the protrusion body is formed even between the neighboring conductors, since the projecting body bottlenecks an adhesive at the time of mounting the semiconductor device on a glass substrate, there is a possibility for the adhesive not to spread uniformly on a mounting surface. For this reason, bonding irregularity can occur, and the deformation amount of the projecting body can become different according to the location of the projecting body on the mounting surface of the semiconductor device, causing a defective connection between the conductor and a terminal of the glass substrate.
In addition, according to the related art disclosed in JP-A-2004-186333, it is possible to simplify the process of manufacturing the semiconductor device and to reduce the pitch. However, for example, if the resin layer is completely removed by using the conductive layers as masks, in a case of mounting the semiconductor device on a glass substrate of a liquid crystal display device, or the like, there is a possibility that the repulsive force of the projecting body will become weak, causing the mounting surface of the semiconductor device not to be fixed parallel to the glass substrate. Further, if the mounting surface of the semiconductor device is not fixed parallel to the glass substrate, there is a possibility that a defective connection between the conductors and the terminals of the glass substrate will occur according to the location of the mounting surface of the semiconductor device.
In addition, in the case of completely removing the resin layer by using the conductive layers as masks, there is a possibility that an adhesive will spread less uniformly on the mounting surface in the vicinities of both ends of a protrusion group composed of a plurality of protrusions in the longitudinal direction of the protrusion group than in the vicinity of the center of the protrusion group in the longitudinal direction. For this reason, bonding irregularity can occur, and the deformation amount of the protrusions can become different according to the location of the protrusions on the mounting surface of the semiconductor device, causing a defective connection between the conductor and a terminal of the glass substrate.